SRC/dsfrk.f(3)

NAME
SRC/dsfrk.f

SYNOPSIS

  Functions/Subroutines
subroutine dsfrk (transr, uplo, trans, n, k, alpha, a, lda, beta, c)
DSFRK performs a symmetric rank-k operation for matrix in RFP format.

Function/Subroutine Documentation

  subroutine dsfrk (character transr, character uplo, character trans, integer n, integer k, double precision alpha, double precision, dimension( lda, * ) a, integer lda, double precision beta, double precision, dimension( * ) c)

DSFRK performs a symmetric rank-k operation for matrix in RFP format.

Purpose:

    !>
    !> Level 3 BLAS like routine for C in RFP Format.
    !>
    !> DSFRK performs one of the symmetric rank--k operations
    !>
    !>    C := alpha*A*A**T + beta*C,
    !>
    !> or
    !>
    !>    C := alpha*A**T*A + beta*C,
    !>
    !> where alpha and beta are real scalars, C is an n--by--n symmetric
    !> matrix and A is an n--by--k matrix in the first case and a k--by--n
    !> matrix in the second case.
    !>

Parameters
    TRANSR

    !>          TRANSR is CHARACTER*1
    !>          = 'N':  The Normal Form of RFP A is stored;
    !>          = 'T':  The Transpose Form of RFP A is stored.
    !>

    UPLO

    !>          UPLO is CHARACTER*1
    !>           On  entry, UPLO specifies whether the upper or lower
    !>           triangular part of the array C is to be referenced as
    !>           follows:
    !>
    !>              UPLO = 'U' or 'u'   Only the upper triangular part of C
    !>                                  is to be referenced.
    !>
    !>              UPLO = 'L' or 'l'   Only the lower triangular part of C
    !>                                  is to be referenced.
    !>
    !>           Unchanged on exit.
    !>

    TRANS

    !>          TRANS is CHARACTER*1
    !>           On entry, TRANS specifies the operation to be performed as
    !>           follows:
    !>
    !>              TRANS = 'N' or 'n'   C := alpha*A*A**T + beta*C.
    !>
    !>              TRANS = 'T' or 't'   C := alpha*A**T*A + beta*C.
    !>
    !>           Unchanged on exit.
    !>

    N

    !>          N is INTEGER
    !>           On entry, N specifies the order of the matrix C. N must be
    !>           at least zero.
    !>           Unchanged on exit.
    !>

    K

    !>          K is INTEGER
    !>           On entry with TRANS = 'N' or 'n', K specifies the number
    !>           of  columns of the matrix A, and on entry with TRANS = 'T'
    !>           or 't', K specifies the number of rows of the matrix A. K
    !>           must be at least zero.
    !>           Unchanged on exit.
    !>

    ALPHA

    !>          ALPHA is DOUBLE PRECISION
    !>           On entry, ALPHA specifies the scalar alpha.
    !>           Unchanged on exit.
    !>

    A

    !>          A is DOUBLE PRECISION array, dimension (LDA,ka)
    !>           where KA
    !>           is K  when TRANS = 'N' or 'n', and is N otherwise. Before
    !>           entry with TRANS = 'N' or 'n', the leading N--by--K part of
    !>           the array A must contain the matrix A, otherwise the leading
    !>           K--by--N part of the array A must contain the matrix A.
    !>           Unchanged on exit.
    !>

    LDA

    !>          LDA is INTEGER
    !>           On entry, LDA specifies the first dimension of A as declared
    !>           in  the  calling  (sub)  program.   When  TRANS = 'N' or 'n'
    !>           then  LDA must be at least  max( 1, n ), otherwise  LDA must
    !>           be at least  max( 1, k ).
    !>           Unchanged on exit.
    !>

    BETA

    !>          BETA is DOUBLE PRECISION
    !>           On entry, BETA specifies the scalar beta.
    !>           Unchanged on exit.
    !>

    C

    !>          C is DOUBLE PRECISION array, dimension (NT)
    !>           NT = N*(N+1)/2. On entry, the symmetric matrix C in RFP
    !>           Format. RFP Format is described by TRANSR, UPLO and N.
    !>

Author
    Univ. of Tennessee

    Univ. of California Berkeley

    Univ. of Colorado Denver

    NAG Ltd.

Definition at line 164 of file dsfrk.f.

Author

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